Tunable dense wavelength division multiplexing transceiver, circuits and devices therefor, and methods for making and using such transceivers, circuits and devices

Abstract

The disclosure relates to a tunable 50 GHz and 100 GHz channel spacing DWDM transceiver, and methods of making and using the same. The transceiver comprises an electro-absorption modulation laser (EML), a system board configured to compare a preset wavelength with an actual emission wavelength of the EML, a microcontroller and one or more associated registers configured to communicate with the system board, a temperature controlling circuit configured to stabilize the actual emission wavelength of the EML; and a wavelength meter connected to the output of the EML and having an output connected to the system board. The system board may be configured to provide a feedback loop from the EML to the microcontroller. The transceiver, suitable for 50 GHz channel spacing standards, can be made from existing standard transceivers and can switch between 50 GHz and 100 GHz channel spacing modes.

What is claimed is: 
     
       1. A transceiver feedback loop, comprising:
 a system board configured to compare, during data communication, a preset wavelength with an actual emission wavelength of an electro-absorption modulation laser, configured to provide feedback data to calibrate and maintain stability of the actual emission wavelength and correct any wavelength variation between the preset wavelength and the actual emission wavelength; 
 a transceiver module, including:
 a micro-controller and one or more associated registers, configured to communicate with the system board and monitor at least part of the transceiver, wherein the one or more associated registers store information for the preset wavelength; 
 a temperature controlling circuit, configured to control the temperature of the electro-absorption modulation laser and stabilize the actual emission wavelength of the electro-absorption modulation laser responsive to said actual emission wavelength; and 
 the electro-absorption modulation laser, wherein the electro-absorption modulation laser is an aged electro-absorption modulation laser; and 
 
 an external wavelength measuring device receiving an optical output of the electro-absorption modulation laser, monitoring the actual emission wavelength, and having an output connected to the system board, 
 wherein said output is indicative of said actual emission wavelength of said electro-absorption modulation laser, and wherein said output is used to correct any wavelength variation between the preset wavelength and the actual emission wavelength. 
 
     
     
       2. The transceiver feedback loop of  claim 1 , further comprising a cooling and/or refrigerating mechanism configured to cool the electro-absorption modulation laser. 
     
     
       3. The transceiver feedback loop of  claim 1 , wherein the wavelength measuring device comprises a wavelength meter. 
     
     
       4. The transceiver feedback loop of  claim 1 , wherein the microcontroller comprises a processing unit. 
     
     
       5. The transceiver feedback loop of  claim 1 , wherein the electro-absorption modulation laser comprises a distribution grating laser diode and an electroabsorption modulator. 
     
     
       6. The transceiver feedback loop of  claim 1 , further comprising a serial bus configured to carry communications between the system board and the microcontroller. 
     
     
       7. A tunable channel spacing DWDM transceiver, comprising the transceiver feedback loop of  claim 1 . 
     
     
       8. The DWDM transceiver of  claim 7 , wherein the register(s) comprise an XFP MSA register configured to store values for the preset wavelength(s). 
     
     
       9. The DWDM transceiver of  claim 8 , wherein the electro-absorption modulation laser emits light at a plurality of preset wavelengths, and the preset wavelengths have a spacing of at least 0.4 nm. 
     
     
       10. The DWDM transceiver of  claim 8 , wherein the electro-absorption modulation laser emits light at a plurality of preset wavelengths, and the preset wavelengths have a spacing of at least 0.8 nm. 
     
     
       11. A method of tuning a dense wavelength division multiplexing (DWDM) device, comprising:
 measuring, during data communication, an actual emission wavelength of an aged electro-absorption modulation laser using a wavelength measuring device external to a transceiver module that includes the aged electro-absorption modulation laser, and feeding back one or more data points about the actual emission wavelength back to a system board; 
 comparing a pre-configured wavelength and the actual emission wavelength to determine a difference; 
 communicating the difference via a feedback loop including the system board to the transceiver module containing the aged electro-absorption modulation laser to calibrate the aged electro-absorption modulation laser and maintain a stability of the actual emission wavelength; 
 communicating information between the system board and the transceiver module to monitor the actual emission wavelength of the electro-absorption modulation laser, the transceiver module having a micro-controller and one or more registers associated with the micro-controller that store information for the preset wavelength; and 
 stabilizing the actual emission wavelength of the electro-absorption modulation laser by correcting any wavelength variation between the pre-configured wavelength and the actual emission wavelength via said feedback loop, wherein an input to said feedback loop is said one or more data points about the actual emission wavelength. 
 
     
     
       12. The method of  claim 11 , wherein the transceiver module comprises a tunable channel spacing DWDM transceiver. 
     
     
       13. The method of  claim 12 , wherein the tunable channel spacing DWDM device is configured to operate in both 50 GHz and 100 GHz transmission modes. 
     
     
       14. The method of  claim 11 , wherein the one or more registers comprise an XFP MSA register associated with the micro-controller. 
     
     
       15. The method of  claim 11 , further comprising cooling the electro-absorption modulation laser. 
     
     
       16. The method of  claim 11 , wherein the electro-absorption modulation laser emits light at a plurality of preset wavelengths, and the preset wavelengths have a spacing of at least 0.4 nm. 
     
     
       17. The method of  claim 11 , wherein the electro-absorption modulation laser emits light at a plurality of preset wavelengths, and the preset wavelengths have a spacing of at least 0.8 nm. 
     
     
       18. The transceiver feedback loop of  claim 3 , wherein the system board calculates a difference between the preset wavelength and the actual emission wavelength by comparing the actual emission wavelength from the wavelength meter with a setting read from one of the one or more associated registers. 
     
     
       19. The DWDM transceiver of  claim 8 , wherein the system board calculates a difference between the preset wavelength and the actual emission wavelength by comparing the actual emission wavelength from the wavelength measuring device with a setting read from the XFP MSA register. 
     
     
       20. The method of  claim 11 , further comprising burning-in an electro-absorption modulation laser for at least about 400 hours to provide the aged electro-absorption modulation laser.